Here is the full list of all 32 The Metronomicon: Slay The Dance Floor achievements.
Defeat every arena challenge.
Purchase every ultimate weapon.
Kill five enemies in a row with a single attack.
Beat the final challenge's omega boss.
Succeed in every single sidequest.
Apply six buffs to one hero at the same time.
Survive every song in Story Mode.
Save the world of Koras from Dancemageddon.
Decompile a fearsome Dance-o-bot.
Unlock Sara's laboratory.
Survive a story song without killing an enemy.
Make five arena challenges your chump
End the dancing of a great Candy Dragon.
Attain a 300 note streak.
Dethrone the Wraith King in the Haunted Kingdom.
Succeed in beating five sidequests.
Survive a story song without healing any party member.
Conquer one challenge in the school arena.
Survive your first 10 songs in Story Mode.
Destroy the Speyeder of the Wild Forest.
Perform a perfect meteor attack counter.
Succeed in your first story sidequest.
Unlock your first bonus song.
Perform a perfect Solo-Lane Team Attack.
Perform your first upgrade to the school.
Attain a 100 note streak.
Defeat every arena challenge on hard.
Survive every song in Story Mode on Hard.
Deal at least 5000 hp damage in one strike as Gwen.
Beat a fifty song playlist without ever pausing.